Tooth flossing is an important part of the regular maintenance of the health of teeth and gums. In its simplest form, floss is dispensed from a container, and each end of a piece of floss is wrapped around a finger on each of the users two hands. The floss is brought into the mouth for use by the motion of both hands. This can be an awkward procedure under the best of circumstances. It is particularly awkward for a person with limited mobility or in circumstances where a person is flossing the teeth of another person such as a dental technician or a person aiding a disabled person or child. Therefore, various attempts have been made to develop implements for simplifying the flossing procedure.
The flossing apparatuses generally have a divergent or fork-shaped head portion with two prongs for holding a piece of dental floss between them. This head portion replaces the fingers that are used in the manual flossing procedure and is the part of the apparatus which is brought into the mouth for doing the actual flossing. The floss must be held relatively taught between the two ends of the prongs to provide a stiff piece of floss for the user to work between their teeth.
The flossing apparatuses also generally have a handle portion which the user can grasp with one hand. While holding the handle, the user can move the forked floss holding end of the apparatus to a proper location for conducting the flossing. There may also be a neck connecting the fork shaped head portion with the handle portion. The neck may make for greater mobility of the apparatus when the fork shaped head portion is inserted in the oral cavity, especially for reaching rear teeth.
While the designs have differed significantly in the shape and orientation of the handle and a fork shaped head portion, an even greater variation exists in the treatment of the dental floss itself in the apparatus. For example, the dental floss can be fixedly attached to the head portion such that the entire head portion must be replaced to refresh the piece of dental floss in position for use. This arrangement is particularly unsatisfactory since the floss may have to be refreshed quite frequently which would make the necessary replacement of the entire head portion both inconvenient and unnecessarily expensive.
Therefore, several designs of flossing apparatuses have contained dispensing spools within the apparatus to supply a source of fresh floss for replenishing the portion of floss in position for use. These apparatuses have a means for cutting off the spent floss once fresh floss has been delivered across the head of the apparatus for use. A tying portion is provided for holding the floss rigidly against the tension produced when using the floss. These designs are not optimal because the spent portion of the floss must be handled by the user for advancing new floss in position for use and for removing the old floss. This is unpleasant when the user is flossing their own teeth, and unhygienic when the user is flossing the teeth of another person. Furthermore, the procedure is time consuming.
To address the problems associated with the disposal of used floss, several designs have incorporated a spool for the specific purpose of taking up the used dental floss. These designs have various degrees of complexity. Several patents have issued for motorized dental floss apparatuses, for example, U.S. Pat. No. 5,176,157, DEVICE FOR SUPPORTING AND OPERATION OF DENTAL FLOSS, U.S. Pat. No. 5,188,133, DENTAL FLOSSING TOOL, and U.S. Pat. No. 5,323,796, AUTOMATED DENTAL FLOSSER. These motorized dental flossing apparatuses have the disadvantage of being relatively expensive and relatively heavy.
Particularly, the U.S. Pat. No. 5,176,157 patent discloses an apparatus with a dispensing reel and a "truncated cone element" upon which used floss winds around. A motor driven mechanism rotates the truncated cone element and simultaneously rotates a small roller with a swinging motion. The mechanism is designed to run continuously during use to replenish the floss continuously. A dispensing reel is associated with a friction drive means with the amount of friction determined by the screwing or unscrewing of a pawl. It is not clear how the winding up of the floss on the truncated cone element is commensurate with the rotation of the small roller, but it is stated that the floss always remains stretched, even though this would not seem to immediately follow from the design. Periodically, the floss must be cut and removed from the cone element. The main focus of the invention is related to the movement of the floss during use rather than the collection of used floss to minimize handling of the use floss.
A variety of manual dental floss apparatuses with dispensing and collecting spools have been designed. U.S. Pat. No. 4,790,336, DENTAL FLOSS APPLICATOR, describes a device with a supply reel of fresh dental floss and a take-up post. Floss from the supply reel wraps around a reel. Rotation of the reel simultaneously advances floss from the supply reel and rotates the take-up post. Since the amount of floss advanced from the supply reel and the amount of floss collected on the take-up post are not the same amounts, the user must put considerable effort into properly advancing the floss. A floss clip must be used to control the removal of floss from the supply reel. Furthermore, the take-up post is not designed to actually collect a significant quantity of the floss dispensed from the supply reel. Therefore, the clip has a cutting edge for removing much of the floss. Given these limitations in the design of the flossing apparatus of the U.S. Pat. No. 4,790,336 patent, it is not particularly convenient for advancing the floss without handling the used floss, and the user must expend considerable effort to properly advance the floss.
U.S. Pat. No. 5,060,681, DENTAL FLOSSING DEVICE, involves a concentric tapered spool and take-up reel. This device attempts to use the tapered spool to maintain tension in the floss as it is advanced. Since the dispensing spool is tapered, a greater amount of floss is dispensed as more floss is used to account for the greater diameter of the effective collecting spool as floss is collected. For this process to work properly, the floss must unwind and collect perfectly as desired. Also, if any excess floss is introduced, there is no means to take up this excess to allow the device to function with the proper tension again. Perhaps the most serious drawback of this design is that there is no simple way to reattach the floss if it has ripped.
U.S. Pat. No. 5,038,806, DISPOSABLE DENTAL FLOSSER AND HOLDER, describes an apparatus with a spool of unused floss and a take-up reel. The apparatus is designed to approximately dispense and collect like amounts of floss from the respective spool or reel. But the apparatus does not have the means to ensure that the floss remains under tension. Therefore, a guide post is provided for the user to wrap floss around if necessary to increase tension. The spool of unused floss is freely rotatable. This requires an unreasonable amount of interaction by the user to maintain the tension in the apparatus.
Similarly, U.S. Pat. No. 5,301,698, MULTIPLE LOCK DENTAL FLOSS HOLDER AND SPOOL ENCLOSURE ASSEMBLY THEREFOR, discloses concentric dispensing and collecting spools. This apparatus would seem to have no mechanism for adjusting for the different diameters on the dispensing spool and neck upon which the used floss is collected. Therefore, the floss will not remain under tension as the floss is advanced without direct intervention by the user.
Previous designs for dental flossing apparatuses have not provided a mechanism whereby the user can advance the dental floss easily with one hand with a minimum of effort while keeping the floss under sufficient tension to allow flossing. This should be possible with a light, manual apparatus. It should be possible to do inexpensively either with a disposable apparatus or one where the dispensing and collection spools are maintained in cartridges that can be replaced. Such an apparatus would have spools that are locked when the user is not advancing the spool. The apparatus should maintain the tension along the floss while the user is advancing the floss without any effort beyond advancing a knob.